Process of drying brick



(No Model J 2 Sheets-Sheet 1.

G.-'J. DION.

PROCESS OF DRYING BRICK. No. 487, 827. 1 Patented Dec. 13, 1892.

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' G. J. DION.

PROCESS OF DRYING. BRIGK,

No. 487,827; Patented Dec. 13,1892.

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v 78677 ggzz-omqya UNITED STATES PATENT OFFICE.

CHARLES J. DION, OF ST. PAUL, MINNESOTA.

PROCESS OF DRYING BRICK.

SPECIFICATION forming part of Letters Patent No. 487,827, dated December13, 1892.

Application filed April 11, 1891. Serial No. 388,444.. (No model.)

To aZZ whom it may concern.-

, Be it known that I, CHARLES J. DION, of St. Paul, Ramsey county,Minnesota, have invented certain Improvements in the Process of DryingBrick, of which the following is a specification.

, In the manufacture of brick, tile, terracotta, and similar materialsthe green stock after being formed requires to be thoroughly driedbefore burning, which process is usually carried out by exposing it inthe open air. The changes in temperature and humidity and of circulationof the atmosphere make this process a very difficult and uncertain one,besides consuming several days time, frequently accompanied by seriousloss caused by unfavorable conditions of the weather. Various attemptshave been made, therefore, for artificially drying the brick in inclosedchambers or kilns, but usually with unsatisfactory results, the currentsof heated air rapidly drying the surfaces of the brick with which theair comes in contact, causing checking and warping,while the centers arestill in a moist state. The moisture thrown ofi from the brick at thebeginning of the process also is to some extent condensed on the ceilingof the chamber and drops back upon the brick, so as to injure, if notruin, the top layers. To secure their perfect and uniform drying, it istherefore essential that there be no strong currents of heated air tostrike upon them, but rather a gentle circulation of the atmospherethrough and about them without currents or dead-air spaces,whereby allof the surfaces as nearly as possible are uniformly dried. It is alsoessential to the best results that this drying process be carried on atthe center of the brick as nearly as rapidly as at the surface, so thatthe contraction shall be uniform and checking and cracking avoided.

I accomplish this result by means of a new humidity of the atmosphere,while its temperature maybe increased. The moisture in the whole mass isthus expelled by the heat, and by proper regulation of the humidityandtemperature the drying process may be carried on practically as rapidlyat the center as at the surface of the brick.

To carry out my improved process, I provide an improved type ofdrying-kiln, usually with two or more independent chambers orcompartments, connected with each of which is a circulating air systemhaving an apparatus for heating the air therein and means formaintaining the circulation. nection of the system with the severalchambers is controlled by valves, whereby the direction of thecirculation in each chamber may be reversed at will or entirely out off.

. Valve-controlled outlets and inlets to the system are also providedfor the discharging of moist air therefrom and the inlet of dry air. Ialso provide means for charging the air with moisture just before itenters the chamber to secure and maintain the proper degree of humidity.

While different means may be employed with more or less efficientresults to carry out my improved process, I prefer to use the apparatusshown in the accompanying drawings, in which I Figure 1 is a verticallongitudinal section of one of the drying-chambers, showing theconnections of the air system and the tracks for carrying the cars ofbrick; and Fig. 2 is a vertical cross-section of the same on line 00 0aof Fig- 1.

In the drawings, 2 represents the side walls of the structure, 4 itsroof, and 6 the outer doors, which should close practically air-tight.The cars 8, loaded with the green brick 10,

are supported on the rails 12, arranged upon the floor 16 of thestructure, or the rails 14, supported above the same on cross-timbers18.

20 is a conduit extending underneath the floor of the structure, inwhich is arranged the main inlet air-pipe 22, while similarly arrangedunderneath the roof, above the chambers, is the return-main 24, whichconnects with thepipe 22 (connection not shown) and forms thecirculating system. Interposed in the system, preferably at a distancefrom and independent of the kiln, is a fan or other means forestablishing a circulation in the system and a heating apparatus toraise the inclosed air to the required temperature. These, however, formno part of my present The con-.

be adjusted at will.

' with the latter by means of the branch pipe 36, having the damper 38,and connected with the chamber by means of the air-pipe 40, having aslotted opening 42 in its top, connecting to the slot in the floor bymeans of the flanges 44. The pipe 46, having the damper 48, similarlyconnects the main 22 with the transverse receiver 50 above the chamber,which is connected to the slot 28 by means of the slotted pipe 52. Thereceiver 34 is connected by means of the pipe 54, having the damper 56,to the main 24, and the receiver 50 is connected with the main 24 by thepipe 58, having the damper 60. The outlet-pipe 62 connects with thetransverse receiver 50 and is provided with the damper 68, the pipe 54being connected with the pipe 62 above its damper by means of the branchpipe 64, having the damper 66. An upward circulation of air through thechamber is established by opening the dampers 38 and and a downwardcirculation by closing said dampers and opening the dampers 48 and 56,and by the alternate opening and closing of said dampers the circulationthrough the chamber is reversed at will. Air is discharged from thesystem by opening either the valve 68 or 66, according to the directionof circulation, and the outer air is admitted to the system by openingthe valve 72 in the inlet-pipe 70.

In order to prevent currents of air in the chamber and to render thecirculation as general and uniform as possible, I provide curveddeflectors 80, supported over the slots 26 upon standards 82, similardeflectors 84 being arranged underneath the slots 28 in the ceiling. Thesteam-pipe 74, connected with a suitable source of steam-supply, isarranged, preferably, underneath the structure parallel with the main 22and connected with the branch pipes of the main 22, which connectionsare controlled by valves 78.

Having thus described the construction of the apparatus, the processitself may be described as follows: The chamber while open to receivethe stock is preferably cut off entirely from the air system in order toprevent waste of the hot air and to permit the prO- cess to be carriedon uninterruptedly in the other chambers. The chamber having been filledwith brick, its doors are closed and the dampers 48 and 56 arepreferably first opened to establish a downward circulation through thechamber. At the same time the damper 78, connecting with the steam-pipe,is opened to charge the air with moisture before it enters the chamber.After the air has circu lated for a time downward throughthe chamber thedampers 48 and 56 are closed and the dampers 38 and 60 opened toestablish an upward circulation, the damper connecting the steam-pipewith the pipe 36 being opened to charge the'air with moisture, asnecessary. This circulation is reversed frequently throughout the entireprocess and as often as necessary to carry on the operation of heat-fing and drying uniformly the tops and bottoms of the brick withoutnecessitating their being turned. The air of the chamber is thusgradually heated by the mingling with it of the hot air from-the system,the temperature and humidity at all times during the process beingindicated and their control'assisted by means of a thermometer and ahygrometer arranged in the chamber, the object, as stated, being tomaintain such a degree of humidity as will prevent any drying of thestock during the first step of the process. The brick in the chamber arethus gradually heated to a high temperature through and through in theirmoist state, when the first part of the process is terminated by cuttingofi the admission of moisture to the chamber and alternately opening thevalves 66 and 68 as the circulation is reversed to permit the gradualescape of the moist air from the chamber, while at the same time thedamper 72 of the intake-pipe is opened to supply the system with anequal amount of dry air. The humidity of the air in the chamber is thusgradually decreased and the moisture slowly expelled from the brick andcarried off with the discharged air, the heat of their mass being suchthat the drying proceeds uniformly from the center of the brick outward.As the stock is thus gradually dried the temperature may be alsogradually increased until the process is completed. The deflectors nextto the slots in the ceiling and floor of the chamber distribute the airthrough the chamber and tend to prevent currents of air, which would drythe surfaces of the brick with which they come in contact too rapidly,and also prevent any dead-air spaces in which the drying process will beunduly retarded.

I claim 1. In the drying of green brick and similar materials in aninclosed chamber by means of a connected circulating hot-air system, theprocess consisting of charging the air with sufficient moisture beforeit enters the chamber from the system to prevent the drying of thestock, circulating the air through the chamber until the stock is heatedthroughout uniformly to a high temperature, and then graduallydecreasing the humidity of the air in the chamber, substantially asdescribed.

2. The foregoing-described improved process of drying green brick andsimilar materials, consisting in first placing the same in an inclosedchamber having a communicating circulating hot-air system, thenadmitting the air from said system into said chamber, charging the samebefore entering with sufficient moisture to prevent drying of the stockuntil it is uniformly heated, reversing the circulation from time totime, and thenv gradually decreasing the humidity of the air in thechamber and increasing its temperature, substantially as described.

3. The foregoing-described improved process of drying green brick andsimilar mate rials in an inclosed chamber by means of a circulatinghot-air system consisting of charging the air before it enters saidchamher from the system with sufficient moisture

